MXSCandinavia on Thumper Talk demonstrated the shim stack modifications needed to separately control low and high speed damping:
- Preloading a soft shim stack increases damping force at low speed and softens damping force at high speed
- A crossover does the opposite producing softer low speed and stiffer high speed damping
- A soft tapered shim stack matches the crossover stack at low speed and drops off at high speed
Tuning shim stacks to get the desired damping force curve is simply done by hacking: adding or removing shim stack preload and crossovers to get the desired damping force curve shape and hacking the shim stack stiffness to get the desired damping force value. Obviously, multiple iterations are needed to simultaneously achieve the desired damping force value and curve shape.
The numerical test bed of Shim ReStackor makes that simple, easy and intuitive.
